Question

A massless spring balance is attached to $2$ kg trolley and is used to pull the trolley along a flat surface as shown in the fig. The reading on the spring balance remains at $10$ kg during the motion. The acceleration of the trolley is: (Use $g=9.8$ $m{s}^{-2}$)

• A. $4.9m{s}^{-2}$
• B. $9.8m{s}^{-2}$
• C. $49m{s}^{-2}$
• D. $98m{s}^{-2}$

Answer 1

The correct option is C $49m{s}^{-2}$

We know that spring will measure the force acting on it, either compression or tension.
Here tensile force is acting on it so spring force$\left(kx\right)=force\left(F\right)$
$F=mg=10\times 9.81=98.1N$
By Newton's second law, $F=ma$

$a=\frac{F}{m}=\frac{98.1}{2}=49.05m{s}^{-2}$